NEW YORK, Jan 10 (Reuters) - The U.S. commercial paper market recorded its largest weekly increase in four years as investors have piled into low-risk money market funds in response to the recent volatility on Wall Street, Federal Reserve data released on Thursday showed.

The jump in these short-term IOUs, which companies use to raise cash to fund their payrolls and inventories, was the biggest weekly gain since a $60.2 billion rise in the week of Jan. 7, 2015.

Accounting for seasonal adjustments, commercial paper outstanding grew to $1.073 trillion, up $27.1 billion which was the biggest increase since the week of Dec. 26, 2017.

Some analysts consider seasonally adjusted readings on commercial paper less reliable than the unseasonally adjusted ones since they have been distorted by the global financial crisis.

Money market funds are major buyers of commercial paper.

Assets of money market funds, which are seen as nearly as safe as bank accounts, jumped $35.62 billion to $3.029 trillion in the week ended Jan. 8. This marked the first time that money fund assets surpassed $3 trillion since the week ended March 9, 2010, the Money Fund Report published by iMoneyNet said on Wednesday.

The amount of commercial paper that money funds regulated by Securities and Exchange Commission can purchase increased by $23.9 billion in the latest week, Fed data showed.